Receiver-assembly for firearms



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T IIJ .IIIII--IIIIIII-II II I IIPIIIIIIIHHIIIIIHIIIIIIIUrI II. I IIIIILI I I I I D. M. WILLIAMS RECEIVER-ASSEMBLY FOR FIREARMS Filed Feb. 2e,1943 April 1o, 1945.

A1131'l 10, 1945. D. M. WILLIAMS 2,373,213A

RECEIVER-AS SEMBLY FOR FIREARMS Filed Feb. 2s, 194s 5 sheets-sheet 2 asmq 4o; 7011111710310," 3s

Apfi l0, 1945. D. M. WILLIAMS 2,373,213

RECEIVER-AS SEMBLY FOR FIREARMS Filed Feb. 26, 1943 5 Sheets-Sheet 5 PH10, 1945- D. M. WILLIAMS 2,373,213

l RECEIVER-ASSEMBLY FOR FIREARMS Filed Feb. 26, 1943 5 sheets-sheet 4 ff36' n s Y @A PR' i0,1945- D. M. WILLIAMS 2,373,213

RECEIVER-ASSEMBLY 'FOR FIREARMS Filed Feb. 26, 1943 5 Sheetsi-Sheet 5 69have, Hrm

Patented pr. l0, 1945 RECEIVER-ASSEBIBLY FOR FIREARMS David M. Williams,New Haven, Conn., assignor to Western Cartridge Company, New Haven,Conn., a corporation of Delaware Application February 26, 1943, SerialNo. 477,207

3 Claims..

The present invention relates to improvements in firearms, and relatesmore particularly to improvements to receiver-assemblies and associatedparts therefor.

One of the objects of the present invention is to provide a superiorreceiver-assembly for firearms which includes a receiver and areceiverplug mounted in the rear end of the said receiver to excludeforeign matter from the same but which is, in addition, so constructedand arranged as to enable the receiver-plug or closure to dischargeother functions by its being shifted from one -position to another.

Another object of the present invention is to provide a superiorreceiver-assembly for firearms' which includes a receiver and arotatable receiver-plug so constructed and arranged as to enable thesaid receiver-plug to function as means for rendering the firearm safeagainst unintentional discharge.

A Vfurther object of the present invention'is to provide a superiorreceiver-assembly of the character referred to and wherein a rotatablereceiver-plug or closure is employed, which latter is so constructed andso related to associated features as to act as a seal for lateralapertures in the receiver proper when the said receiver-plug is rotatedinto one of its functioning positions.

A still further object of the present invention is to provide a superiorfirearm-structure comprising a receiver, a rotatable receiver-plug and areciprocating breech-bolt, and so constructed and arranged as to enablethe said receiver-plug to function as releasable restraining-means forrestraining chosen movements of the said breechbolt.

With the above and other objects in, View, as will appear to thoseskilled in the art from the present disclosure, this invention includesall features in the said disclosure which are novel over the prior artand which .are not claimed in any separate application.

In the accompanying drawings, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a broken view partly in side elevation and partly in verticalcentral-longitudinal secf tion of the'central portion of a firearmembody- -ing the present invention and showing the hammer as cocked andthe rotary receiver-plug in its normal position wherein the rearm may bedischarged at will;

Fig. 2 is a top or plan View thereof;

Fig. 3 is a view similar to Fig. 1 though less comprehensive and showingthe rotary receiverof Fig. 3; 1 Fig. 9 is a broken transverse sectionalView plug turned into its safety position to effect the Fig. 7 is abroken detail transverse sectional View taken on the line 1-`| of Fig.1;

Fig. 8 is a similar view taken on the line 8 taken on the-line 9--9 ofFig. 3;

Fig. 10 is a broken top or plan View of the receiver, the rear portionof the barrel, and associated parts, and showing the rotary receiver-'plug turned into its safety position and the.

breech-bolt and action-slide partly retired;

Fig. 11 is an underside view of the structure Fig. 14 is a broken Viewof the structure partly in side elevation and partly in verticalcentrallongitudinal section, and showing the breech-bolt retired to thelimit of its rearward movement, preparatory to being locked intosubstantially the said position by the partial rotation of thereceiver-plug Fig. 15 is a view similar to Fig. 14 but in side elevationonly and showing the receiver-plug turned suiiciently to eiect thelocking-back of the breech-bolt and hence also the locking-back of theaction-slide;

Fig. 16 is a top or plan view of the structure shown in Fig. 15; i

Fig. 17 is a transverse sectional view taken on' the line I'I-I'l ofFig. 14; f Fig. 18 is a similar View taken on the line |8-l of Fig. 15;

Fig. 19 is a broken longitudinal sectional View taken on the line I9--I9of Fig. 15 with a portion t of the receiver in plan;

Fig. 20 is a perspective view of the rotary re ceiver-plug viewing thesame mainly from the top;

Fig. 21 is also a perspective view of the receiverplug but viewing thesame mainly from the undercommonY in firearm-structures.

Fig. '22 isa top or plan view of the receiver depresent inventionincludes a stock 30 which supports ia receiver 3|, a trigger-plate 32`and a bar'- The said barrel 33 is rigidlyr attacl'nedy rel 33.

at its rear end to the. receiver 3| in a .manner Throughout the majorportion of its iength,r the barrel 33 has extending over its upperportion a barrel-cover.

' 34 which like thestock 3|! is preferably formed of wood or otherheat-insulating f and shockabsorbing material. A

The receiver 3| yabove referred tois formed with a bore ormechanism-receiving chambery 35 extending longitudinally therethroughand 'having acontour rwhich is substantially cylindrical in lcharacter.Reciprocating'and oscillating in the mechanism-receiving chamber 35 inthe'receiver 3| is 'a breech-bolt 36 which throughout `the majority ofits length is of cylindrical formext'eriorly and which is formed at itsforward end with a relatively-short radially-extending ioclring-lug 3Tand a diametrically-opposte andy relatively-long combinedoperating-and-locking lug y33. Both of the lugs 351 and 38 fit intosuitable l recesses in the'receiver '3| when the breech-bolt `is at thelimit of its forward-movement, fao-effect ably guidedfor movementlengthwise of the rethe locking' ofthe breech-bolt ink such position.

` The breech-'bolt 36 has the outer portion of its combinedoperating-and-loelring lug" 38 projecting into a cam-recess 39 formedinthe inner face ofv the rear portion of an action-slide generallydesignated by the reference character 40. The coaction of the lug 38 andthe surfaces ofthe cam-recess 39 serve to operatively interconnect theaction-slide 4|) and the breech-bolt 36 for effecting the movement ofthe latter in a manner well known in the art and corresponding generallyto the operative interconnection employed in the well-known Garandmilitary rifle.` In its rear portion, the action-slide 43 is also formedwith an outwardly-extending operatinghandle 4| by means of which theaction-slide itself and also the breech-bolt 36 connected thereto may beretired in a manner" as will here-vv inafter appear.

At its forward end, the action-slide 4U is formed with an integral headgenerally designated by the reference character 42 and including a.transversely-extending relatively-heavy end-wall 43. From the perimeterof the head 42 just referred to, a relatively-thin lateral-wall 44extends forwardly and normally laterally envelops a cylinder-lug 45 whenthe parts are in the positions in which they 'are shown in Fis. 1.

The cylinder-lug 45 above referred toiis formed integral with andoffsets downwardly from ythe barrel 33 adjacent the rear end of thelatter. The said cylinder-lug is formed with a rearwardly-openingpiston-chamber 46 having its longitudinal axis extending in substantialparallelism with the longitudinal axis of the barrel 33. Leadingforwardly and upwardly from the closed front end of the piston-chamber46 is an inclined gas-passage 41 communicating at its as'ramsforwardupper end with the borey 48 of the barrel 33 so asto conduct gasunder pressure from the said bore to the forward portion of thepistonchamber 46 for purposes as will hereinafter appear.

cylinder-lug 45 is a rpiston generally designated by thereference-character 49. The said piston includes 'arelatively-large-diametered head 5t having ar substantially-gastightreciprocating fit in.` the .forward-portion of the piston-chamber 46,and a rearwardly-projecting.stem 5|. The saidste'm 5| of the piston43fprojects rearwardly through a bushing 52 which is threaded into therrear portion of the rearwardly-opening pistonf chamber 46 `in thecylinder-lug 45.

n The rearward movement of the piston 49 is limited by the engagement ofthe conically-fcontoured rear fa'ce of its head 5U' with thesimilarly-contoured forward edge of the bushing 52. The stem 5| of thepiston 49 normally has its rear end limpinging against the forward faceof the relatively-heavy end-wall 43 of the head 42 `of the action-slide40, :as is sho-wn in Fig. 1.

The action-slide 46 abovereferred to is suitarm-structure in anysuitable manner not requiringdetailed description herein. The saidactionslide, liowever,v is yieldingly yurged forwardly into;

the position in which it is shown in Figs. 1 and 2,

by a helical breech-closing spring 53 acting at its forward end throughtheintermediary of u breech-closing plunger 54. The .rear poi-tion ofthe breech-closing rplunger fits within the forward end of thebreech-closing spring 53 while its forward end. is engaged with theend-wall 43 of the action-slide head 42.v Thebreech-closing spring 53extends rearwardly into a longitudinal spring-pocket 55 formed in theright. side-wall' y of the receiver 3|.

the action-slide 40 the breech-closing spring 33 exerts a constant butyielding effort to maintain the said action-slide in its foremostposition :and hence also acts through the intermediary of the saidaction-slide to maintain the breech-bolt 3B in its breech-closingposition.

- The stock 30 before referred to includes a buttstock-portion 5G and anintegral forestock-portion 51. At about the junction-point of itsbuttstock-portion 56 and forestock-portion 5l, the stock 30 is formedwith a vertical-longitudinal passage 58 extending therethrough from topto bottom and designed and adapted for the reception of portions of thefirearm-structure, including the trigger-plate 32 before referred to andas is especially well shown in Fig. 1. Leading forwardly from thevertical-longitudinal passage 58 just referred to is a relatively-deepupwardlyopening longitudinal groove 5B located mainly in the upperportion of the forestock-portion 5l.

Leading rearwardly from the upper rear-portionv of thevertical-longitudinal passage 58 in the stock 3|) is a longitudinalgroove 60 which is relatively shallow as compared to the groove 59before referred to. Leading downwardly from the groove 60 just referredto is an upwardly-opening shallow recess 6| which communicates at itsforward end with the rear end of the vertical-longitudinal passage 58,as is especially well shown in Figs. 1 and 3. The lower portion of therear-wall of the passage 58 is formed with a notch 62 in which isinstalled a head-plate 63l Extending vertically between the shallowrecess 6| and the notch 62 and in the portion of the Reciprocating inthe piston-'chamber 4K6 of the stock lying immediately to the rear ofthe passage 53 therein, is a vertical cylindrical passage B4. Installedpartly in the upwardly-opening recess 6| and partly in the verticalcylindrical passage 64 is a tensioning-xture 65 having acylindrically-contoured upper face substantially corresponding intransverse curvature to the transverse curvature of the underside of thereceiver 3|.

Inserted upwardly through the head-plate 63 and threaded into the lowerend of the tensioning-fixture 65 is the relatively-large-diameteredbody-portion 66 of a tensioning-screw or member 6l. Formed integral withand upwardly-extending from the body-portion of the tensioning-screw 6lis a relatively-exible tensioning-pin B8 normally projecting upwardlythrough a couplingpassage 69 formed in the lower rear-portion of thereceiver 3|.

The trigger-plate 32 before referred to is coupled in any approvedmanner tothe under-portion of the receiver 3| and coacts with theassembly comprising the head-plate 63, tensioning-fixture 65 andassociated parts in a manner not requiring detailed descriptionhereinbut shown and described in detail in copending application SerialNo. 473,111 led January 21, 1943.

Mounted in the trigger-plate 32 and normally extending upwardly intothel mechanism-receiving chamber 35 of the receiver 3| is a hammergenerally designated by the reference character 1|) and turning upon ahammer-pin '1| extending transversely of the said trigger-plate 32. Thesaid hammer 19 is formed on its forward upper face with an impact-lug'l2 which is adapted to strike the rear-face of the laterally-projectinghead 73 of a firing-pin M t0 effect the discharge of the rearm. The saidfiring-pin 74 is carried by and reciprocates in the breech--boli-l 36before described, in a manner familiar to those skilled in the art. Thehammer 10 is provided with a downwardly-and-rearwardly-extendingintegral hammer-tail 15 having on its lower forward corner acooking-abutment 1B which is adapted to be engaged by the under-face ofa Sear-nose 'Il' rearwardly extending from the upper end of a scar-arm18 forming an integral feature of a trigger 19. The said trigger 19 ismounted for pivotal movement upon a. trigger-pin extending transverselyacross the 4lower rear-portion of the trigger-plate 32.

For the purpose of swinging the hammer 'Ill in a clockwise direction (asviewed in Fig. 1), a helical hammer-spring 8| is employed. The saidhammer-spring 8|, in the instance shown, encircles a, plunger B2 andthrusts the same generally in an upward direction. The outer end of theplunger 82 bears in the under portion of the hammer-tail 'l5 near thejunction thereof with the main portion of the hammer, while the oppositeend of the said plunger reciprocates in a ,trunnion-block 83 pivoted inthe trigger-plate 32. As shown, the lower or inner end of the hammerFspring 8| "pears upon the upper surface of the trunnion-block 83 and byurging the plunger 32 outwardly, the said hammer-spring serves, in turn,to urge the hammer 10 to turn in a clockwise direction when released bythe Sear-arm 18.

The receiver 3| before referred to generally speaking is of tubular formthough at its rear end the upper wall of the receiver is cut away tosubstantially the horizontal median line of the receiver to form areceiver-lip 84 substantially of semioircular form in cross sectionhaving the coupling-passage 69 before referred to located in the bottomportion thereof. Formed in the upper right-hand wall-portion of thereceiver 3| and leading forwardly from the rear end thereof is aguide-slot 85. At its forward end the guide-slot 85 is widened outtoward the left side of the receiver to provide, in eiect, anejection-opening 85 through which cartridge-cases may be ejected whenthe breech-bolt 3G is retired rearwardly. In its lower wall forwardly ofthe receiver-lip 94, the

'receiver 3| is formed with a clearance-passage 70a leading downwardlyfrom the mechanism-receiving chamber 35 in the receiver and providingfor the movement of the hammer lli).

The receiver-lip 84 at the rear end of the receiver 3| is formed with aseries of parallel coupling-ribs 81 extending crosswise thereof andfollowing the cylindrical contour of the inner or upper face of the saidreceiver-lip 84 as is especially well shown in IFigs. 22 and 23.

lFitting within the otherwise open rear-end of the mechanism-receivingchamber 35 of the receiver 3| is a receiver-plug or closure generallydesignated bythe reference character 88. The said receiver-plug iscylindrically contoured, and generally speaking may be said to be ofrelativelydeep cup-shaped form and comprising an endwall 89 and asubstantially-annular lateral-wall 90 integral with and projectingforwardly from the said end-wall 89. On the periphery of its rearportion, the receiver-plug 88 is formed with a series of coupling-ribs9| respectively spaced from each other in a direction longitudinally ofthe receiver-plug and extending around substantially the lower half ofthe periphery of the said receiver-plug. The said coupling-ribs 9| ofthe receiver-plug 88 normally intert between the similarly-shapedcoupling-ribs 8l formed in the upper surface of the receiver-lip 84.,Ihe lengths of both of the sets of coupling-ribs 8l and 9| in adirection circumferentially of the receiver-plug 88 are slightly lessthan 180 to permit the disengagement of the said sets of coupling-ribsone from the other in a manner as will hereinafter appear. Normally,however, when the couplingribs 9| of the receiver-plug 88 areinterengaged with the coupling-ribs Sl of the receiver-lip 84, the saidreceiver-plug is rmly locked in place in the rear-portion of themechanism-receiving chamber 35 of the receiver 3| against axialdisplacement and with capacity, however, for transverse turningmovement, all for purposes as.will more fully hereinafter appear. l

Radially projecting from the rear portion of the outer periphery of thereceiver-plug 98 is an integral lug 92. Extending radially through theend-wall 89 of the receiver-plug lili and also radially outwardlythrough the said lug 92 is a socket 93. Mounted in the inner end of thesaid socket is a helical spring 9d which loutwardly urges a plunger 95mounted in the outer portion of the said socket S3 and normallyprojecting outwardly beyond the outer end thereof for pur poses as willpresently appear.

Fitting over the radial lug 92 at the rear end of the receiver-plug 83is a hollow finger-piece 96 pivoted to the said lug 92 by a pivot-pin 91located forwardly of the spring-pressed plunger 95 and extendingsubstantially perpendicularly with respect thereto as is especially wellshown in Figs. 2 and 19. The spring-pressed plunger 95 presses outwardlyupon the portion of the ringerpiece 96 located to the rear of thepivot-pin 91 yand hence exerts a yielding effort, under the force of thespring 94, to turnthe finger-piece 99 in a counterclockwise direction asviewed in Figs. 2 and 19. At its forward portion, the nger-piece 98 isformed with an integral inwardly-projecting' tang 98 which, in a manneras will hereinafter appear, serves to releasably retain the receiverplug88 in any one of a plurality of positions of rotation within the rearend of the mechanismreceiving chamber 35 in the receiver 3l. On occasionthe inner end of the tang 98 just referred to is adapted to fit into aclearance-notch 99 formed in the periphery of the receiver-plug 88.

Inthe portion of its periphery having couplingribs Si thereon, thereceiver-plug 88 is formed with a circumferentially-extendinglimiting-slot IBG which receives the upper end of the tensioning-pin 68before referred to. The coaction of the respective opposite ends of thelimiting-slot lilo with the respective opposite sides of the upper endof the tensioning-pin 68 serves to limit the rotation of thereceiver-plug 88 so long as the receiver 3! and associated parts remainassembled with the stock 3E.

Adjacent one end of the transverse limitingslot It!) just above referredto, the receiver-plug S8 is formed with a longitudinal clearance-slot Ilwhich i designed to provide clearance for the laterally-projecting headi3 of the firing-pin c 1d in a manner as will hereinafter appear. Theforward portion of the clearance-slot ll is relatively wide in adirection circumferentially of the receiver-plug and extends to andintersects the forward end of the said receiver-plug, as is especiallywell shown in Fig. 21. The forward portion of the longitudinalclearance-slot |01 also serves on occasion to accommodate theradiallyprojecting locking-lug 31 at'the forward end of the breech-bolt3E under conditions as will hereinafter appear. About midway of itslength, one wall of the longitudinal clearance-slot lill is shaped toprovide a sloping hammer-retiring cam 02 which serves to coact with theupper end of the hammer li! to forcibly retire the same in a manner aswill hereinafter appear.

At a point substantially diametrically opposite the relatively-wideforward end of the longitudinal clearance-slot lill above referred to,the receiver-plug 8S is formed with another longitudinal clearance-slotID3 which intersects the forward end of the receiver-plug and extendsbut a relatively-short distance rearwardly therefrom. The last-mentionedclearance-slot 103 is adapted to receive the combinedoperating-andlocking lug 38 which projects radially from the forward endof the breech-bolt 36 at a point substantially diametrically oppositethe lockinglug 32' thereon. Formed integral with one wall of theclearance-slot 03 and projecting circumferentially in a counterclockwisedirection therefrom, is a bolt-retaining finger |84 having arearwardly-facing bolt-retaining abutment 105 which latter is adapted toengage on occasion with the forward face of the combinedoperating-andlocking lug 33 of the breech-bolt 36 to restrain the samein its retired position, all in a manner as will hereinafter appear.

As will be apparent from the foregoing, the receiver-plug 8f3 is adaptedto be turned about its longitudinal axis within the rear-end of themechanism-receiving chamber 35 in the receiver 3 I, to various degreesfor various purposes as will hereinafter appear. The said receiver-plugmay beturned manually by means of its pivotal fingerpiece 96.

Before proceeding to describe the operation of the firearm-mechanismshown and described', it is thought best to first outline some of thefunctions of the receiver-plug 88.

Amongpthe functions-discharged by the receiver-plug cmay' be mentionedthe following:

l(a.) Serves as a. closurefor the rear-end of the receiver 3| to excludeforeign matter therefrom.;

(b) Serves as a closure for the rear-portion of the guide-slot in thereceiver 3l`when the receiver-'plug is turned into its so-called safetyposition and when the breech-bolt is in its forward breech-closingvposition;

(c) The inner face of its end-wall 89 serves as a stop to check therearward movement of the breech-bolt as the same is thrown backfollowing the discharge of the firearm;

(d) Serves to retire and lock the hammer l0 or other firing-memberagainst turning movement to effect the discharge of the firearm, whenthe receiver-plug is turned into its so-called safety position;

(e) Serves when in its safety position to permit but limit the rearwardtravel of the breechbolt so as to allow the same to be retired to adegree suicient for the user to ascertain the presencel or absence of acartridge in the cartridgechamber of the firearm but without permittingthe full extraction and ejection of such cartridge; and

(f) Serves to releasably hold the breech-bolt in substantially itsfully-retired position.

OPERATION Let it be assumed that the hammer is cocked as shown in Fig.l, and that the receiver-plug 88 is turned into its so-called ringposition as shown in Figs. 1, 2, 5 and 7. The term firing position asemployed herein refers to the position of the receiver-plug 8B when thesame is in a position of non-interference with the discharge of thefirearm.

With the hammer l0 cocked as shown in Fig. 1, the rearm may bedischarged by pulling rearwardly upon the finger-piece of the trigger'I9 to thereby release the hammer 10 to the action of the hammer-spring8l Upon its release, the hammer 1B will snap rapidly in a clockwisedirection to impinge its impact-lug 12 against the head 'I3 of thefiring-pin 14, thereby driving the same forwardly and effecting thedischarge of the rearm in a manner well understood in the art.

As soon as the firearm is discharged, gas under pressure from the bore48 of the barrel 33 will pass downwardly through the inclinedgas-passage 4'! into the forward end of the piston-chamber 46. The entryof gas under pressure into the piston-chamber as just described willserve to force the piston 49 rearwardly to correspondingly move theaction-slide 45. The rearward travel of the piston 49 will continue ashort distance until the rear face of its head 50 engages with theforward edge of the bushing 52. The action-slide and associated partswill, however, continue by virtue of their now-acquired momentum to movea much greater distan-ce rearwardly, i. e., until the breech-bolt 36 hasreached substantially the position in which it is shown in Fig. 14wherein its rearward movement is checked by the forward face of theend-wall 89 of the receiver-plug 88.

In traveling rearwardly as above described, the action-slide 4E! willact through its cam-recess 39 to iirst partly turn the breech-'bolt 36in a counterclockwise direction and then to move. the same rearwardlyinto the position in which it is shown in Fig. 14. In the figurereferred to it will be noted that the combined operating-and-locking lug38 has been accommodated in the longitudinal clearance-slot |03 whileunder these conditions the diametrically-opposite locking-lug 31 of thebreech-bolt will be accommodated in the fori'ilalrd `portion of therelatively-wide clearance-slot The rearward movement of the breech-boltas just above described will, in a manner well understood in the art,effect the extraction and ejection of the case of the just-firedcartridge.

Following the full retirement of the breech-bolt as above described, thebreech-closing spring 53 will assert itself and again restore the partsto the positions in vwhich they are shown in Figs. 1 and 2 preparatoryto another discharge of the The safety setting of the receiver-plug 88When the hammer is cocked and the firearm is in readiness for dischargeas shown particularly well in Figs. l and 2, the firearm may be renderedsafe, so to speak, by first swinging the forward portion of thefinger-piece 90 of the receiver-plug 88 outwardly and rearwardly andthen raising the said finger-piece to thereby turn the saidreceiver-plug in a counterclockwise direction (as viewed from the rearof the firearm). In this manner the parts just referred to will shift;from the positions in which they are shown in Figs. 1, 2, 5 and '1 intothe positions in which they are shown in Figs. 3, 4, 6 and 8. Theswinging of the finger-piece 96 (prior to being lifted) about itspivot-pin 91 is to retire its tang 98 outwardly from the clearance-notch99 'in the receiver-plug and from beneath the upper wall of thelongitudinal guide-slot 85. Then upon being lifted as described, thetang 98 of the finger-piece 96 will come to rest in a stop-notch |06 inthe upper wall of the receiver 3|.

The turning movement of the receiver-plug 88 as above described willcause the hammer-retiring cam |02 thereof to act against the adjacentupper portion of the hammer 10 and thereby swing the same in acounterclockwise direction into the position in which the said hammer isespecially well shown in Fig. 3, and thereafter interpose the portion ofthe lateral wall 90 `of the receiver-plug between the said hammer andthe firing-pin 14. Thus, the 4hammer 10 is retired into a so-calledover-cocked position and positively retained therein by thereceiver-plug so that when the latter is restored to its so-calledfiring positionthe hammer will swing in a clockwise direction and againbe caught by the scar-nose 11 of the scar-arm 18.

In turning the receiver-plug 88 from its firing position (Fig. 1) intoits safety position (Fig. 3), should the operator attempt to swing thefingerpiece 96 so that its tang 98 moves beyond the stop-notch |06 inthe receiver, the engagement of one wall of the transverse limiting-slot|00 with the upper end of the tensioning-pin 68 will serve to check suchmovement.

In its turning movement as above described the receiver-plug 88 remainsfirmly coupledto the receiver 3| against axial movement relative theretoby the interlocking effects of the two sets of coupling-ribs 81 and 8|.

After the firearm has been rendered safe as above described,vthe user ofthe firearm will on occasion commence to wonder as to whether or not thefirearm is loaded. With ordinary firearms the user will draw back uponthe breechbolt to secure an answer to the question and in most instanceswill unintentionally extract and eject a cartridge if one is at the timein the cartridge-chamber of the firearm. It is very difficult inordinary firearms to withdraw the breechbolt only partly, since thestart of the retirement of the breech-bolt is usually the most diiiicultand, following its starting, the breechbolt moves relatively easily,with the result that before the user knows what has happened thecartridge is completely extracted and ejected and in all probabilitylost in the dirt. With the present construction, however, and when thereceiver-plug is in its safety position, the user of the firearm mayreadily secure an answer to the question as to whether or not acartridge is'in the cartridge-chamber by moving the breechboltrearwardly by means of the action-slide 40. The rearward movement of thebreech-bolt will, however, be limited to a distance corresponding to buta fraction of the length of the cartridge, due to the fact that thelaterally-projecting head 13 of the firing-pin 14 will engage with aforwardly-facing stop-abutment |01 located on a forward edge of thereceiver-plug adjacent one side of the circumferentially-widenedforwardportion of the longitudinal clearance-slot i0! in thereceiver-plug 88 just forwardly of the hammer-retiring cam |02 therein.

In this manner the user of the rearm will be able to ascertain thepresence or absence of a cartridge in the cartridge-chamber of thefirearm without running the hazard of unintentionally eifecting theejection of such cartridge, due to the unintentional full retirement ofthe breech-bolt.

It is also to be noted that when the receiverplug 88 is turned into itssafety position which is the normal position under which the firearmwould be carried, the lateral wall 90 of the receiver-plug has swunginto position whereby it acts as a closure for the rear-portion of thelongitudinal guide-slot in the receiver 3| to thereby effectivelyexclude foreign matter from the interior of the' receiver. Under theconditions just described, the ejection-opening 8S and associated cutsor openings in the receiver are closed by the periphery of thebreech-bolt 36 itself.

The bolt-retaining position of the receiverplug 88 As is well known tousers of rearms, it is very often desirable to hold a breech-bolt in itsfully-retired position and in the present structure and as has beenbefore noted, the receiverplug 88, or its equivalent, is designed toeffect' such result.

When it is desired to hold the breech-bolt 36 in substantially itsrearrnost position, the said breech-bolt may be retired into suchposition by drawing rearwardly upon the action-slide 40 to bring theparts into the positions in which they are shown in Fig. 14. Thismovement is accomplished while lthe receiver-plug S8 is in its so-calledfiring position, as shown.

When the breech-bolt is retired as just described, its combinedoperating-and-locking lug 38 will be entered into the longitudinalclearance-Slot |03 in the forward part of the lateral wall 90 of thereceiver-plug, so that the front face of the said lug 38 will be locatedrearwardly of the plane of the bolt-retaining abutment |05 of thereceiver-plug 88. f

With the breech-bolt retired and positioned as just above referred to,the same may be latched or retained in such position by rotating thereceiver-plug 88 in a counter-clockwise direction from its .so-calledfiring position into the position in which it is shown in Figs. 1.5, 16,18 and 19, which position is one intermediate its ring position andsafety position.

When the receiver-plug 58 is swung from ,its ring position into itsbolt-latching position, the bolt-retaining finger IFM of the saidreceiverp-lug will be .shifted intoa position Ain front of the combinedoperating-and-locking plug 38 of the breech-bolt. Now when thebreech-bolt 36 is freed of manual restraint, the breech-closing springEdv/ill assert itself and endeavor to rcturn the breech-bolt andassociated parts to their foremost positions. The interposition Of thebolt-retaining abutment HB of the receiverplug in the path of returnmovement `of the breech-bolt will, however, check such forward movement.The tang 98 of the iinger-piece 95 of the receiver-plug 88 will underthe conditions just described rest upon the sloping upper wall of theguide-slot 85 in the receiver Si. The parts will b-e restrained in thepositions just referred to by the friction between the abutment 195 landthe front face of the lug 38 of the breech-bolt.

A slight manual pressure exerted upon the upper face of the finger-piece96 of the receiverplug d8 will serve to turn the receiver-plug from itsbolt-retaining position into its firing position and thereby release thepreviously-latched breech-bolt and associated parts for forward movementinto the positions in which they are particularly well shown in Figs. land 2, in readiness for the discharge of the firearm. The release of thebreech-bolt from its retention may also be effected by slightlyrearwardly moving the breech-bolt to thereby relieve the frictionbetween the parts 3g and |85.. This action will permit the spring Qd toact through the finger-piece S5 and the tang 28 to cause the latter, bycamming action on the sloping upper wall of the guide-slot 35, to returnthe receiverplug 83 to its ring position.

When the finger-piece 96 is swung downwardly, its tank 93 will swinginwardly beneath the upper wall of the guide-slot 85 in the receiver 3land enter the clearance-notch 99 in the periphery of the receiver-plug88. In this .manner the receiver-plug is latched in its ring position toguard against the unintentional or accidental movement thereof out ofsuch position. To effect the turning movement of the receiver-plug outof its firing position, it is first necessary to swing the finger-piece9G thereof so as to withdraw the tang 93 from beneath the upper wall 4ofthe guideslot 85 in the receiver 3l The 'femoral of the receiver-plug 88 from the receiver In order to remove the receiver-plug 88 from thereceiver, it is first necessary to dismount the unit comprising thereceiver 3l, trigger-plate 32, barrel 33 and associated parts from thestock 30. This removal serves to completely remove the coupling-passageSi! in the receiver-lip 84 from the upper end of the tensioning-pin 88.

Now by swinging the tang of the finger-piece 96 of the receiver-plug saoutwardly, the entire receiver-plug may be turned substantially 180 in acounterclockwise direction from its firing position into its releasingposition, as indicated in Figs. l2 and 13. The rotation of thereceiverplug 88 to the extent just referred to will serve to completelydisengage its series of couplingribs 9| from the similar coupling-ribs81 of the receiver-lip 84. Thereceiver-plue 88 may now be Withdrawnaxially rearwardly completely out of the Vrear end of the receiver 3l,as indicated by broken lines in Fig. 12. Following the removal of thereceiver-plug 88, the breech-bolt 3.6 may be removed through thenow-open rear end of the receiver after the action-slide 40 has beendisengaged from the lug 38 of the breech-bolt.

General considerations For purposes of description, the hammer 1D, thefiring-pin 14 and the breech-bolt 36 may be viewed as comprisingportions of a firing-mechanism, since the said parts are jointly andseverally involved in effecting the discharge of the firearm.

The receiver-plug 88 or its equivalent as thus constructed and arrangednot only serves to positively lock the hammer against moving into itsfiring position but also acts as a stop for the breech-bolt when thesame is `thrown fully backwardly as a result of the discharge of thefirearm. The said receiver-plug also acts as a stop to limit therearward movement of the breechbolt to a slight distance as shown inFigs. 10 and l1, to permit the ascertainment of the presence or absenceof a cartridge in the cartridge-chamber of lthe firearm. In addition tothe functions just described, the receiver-plug 88 excludes foreignmatter from entry directly into the rear end of the receiver and alsoexcludes foreign matter from radial entry into the receiver through itsguide-slot when the receiver-plug is turned into its safety position.Also and as before noted, the receiver-plug may be utilized to hold backthe breech-.bolt in its fully-retired position.

The invention may be carried out in `other specificways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange `of the appended claims are intended to be embraced therein.

I claim:

1. A firearm-structure including in combination: a receiver having a.longitudinal mechanismreceiving chamber therein intersecting its rearend; a transversely-oscillatable receiver-closure located at the rear ofthe said receiver in position to close the rear end of themechanism-receiving chamber therein; Coupling-means constructed andarranged to releasably couple the said receiver-closure to the saidreceiver against axial displacement but with capacity for transverseoscillating movement with respect thereto; a breech-bolt reciprocatingin the mechanism-receiving chamber of the said receiver adjacent thevsaid receiver-closure and having a rearwardlyfacing stop-abutment; aforwardly-facing stop abutment carried by the said receiver-closureandmovable by a transverse oscillating 4lfrlovcmenfof the saidreceiver-closure into and out Qf potion to engage with the stop-abutmentof the Said breech-bolt to block the normalrearward movement of the saidbreech-bolt.; apivotal hammer extending in the mechanism-receiving.chamber of the said receiver adjacent the said receiverclosure; andblocking-means carried by the v said receiver-closure and movable yby atransverse oscillating movement of the said receiver-closure intoposition to coact with the said pivotal hammer to block the firingmovement thereof coincidentally with the movement of the aforesaidforwardly-facing stop-abutment into` position .to

engage with the rearwardly-facing stop-abutment of the said breech-bolt.

2. A rearm-structure including in combination: a receiver having alongitudinal mechanism-receiving chamber therein intersecting its rearend and also having a lateral opening leading outwardly from the saidmechanism-receiving chamber; a transversely-oscillatable hollowreceiver-closure located at the rear of the said receiver in position t0close the rear end of the mechanism-receiving chamber therein and havinga lateral opening movable by a transverse oscillating movement of thereceiver-closure into and out of registration with the' lateral openingin the said receiver; coupling-means constructed and arranged toreleasably couple the said receiverclosure to the said receiver againstaxial displacement but with capacity for transverse oscillating movementwith respect thereto; a breech-bolt reciprocating in themechanism-receiving chamber of the saidreceiver adjacent the saidreceiverclosure and provided with a laterally-projecting lug movableinto and out of the respective lateral openings in the receiver andreceiver-closure, the said breech-bolt having a rearwardly-facingst-opabutment; a forwardly-facing stop abutment carried by the saidreceiver-closure and movable by a transverse oscillating movement of thesaid receiver-closure into and out of position to engage with thestop-abutment 0f the said breech-bolt to block the rearward movementthereof; a pivotal hammer extending in the mechanism-receiving chamberof the said receiver adjacent the said receiver-closure;andblocking-means carried by the said receiver-closure and movable by atransverse oscillating movementl of the said receiverclosure intoposition to coact with the said pivotal hammer to block the ringmovement thereof when the said receiver-closure is oscillated intoposition to bring its lateral opening out of registration With thelateral opening in the said receiver coincidentally with the movement ofthe aforesaid forwardly-facing stop-abutment into positionto engage withthe rearwardly-facing stop-abutment of the said breech-bolt.

3. A rearm-structure including in combination: a receiver having alongitudinal mechanism-receiving chamber therein intersecting its rearend and also having a lateral opening leading outwardly from the saidmechanism-receiving chamber; a transversely-oscillatable hollowreceiver-plug extending within the rear of the mechanism-receivingchamber in the said receiver in position to close the same, the saidreceiver-plug also having a lateral opening movable by a transverseoscillating movement of the receiver-plug into and out of registrationwith the lateral opening in the said receiver; couplingmeans constructedand arranged to releasably couple the said receiver-plug within the saidreceiver against axial displacement therein but with capacity fortransverse oscillating movement with respect-thereto; a breech-boltreciprocating in the mechanism-receiving chamber of the said receiveradjacent the said receiver-plug and provided With a laterally-projectinglug movable into and outl of the respective lateral openings in thereceiver and the receiver-plug, the said breechbolt having aforwardly-facing retaining-abutment on its said lug; a rearwardly-facingboltretaining abutment carried by and located in the lateral opening inthe said receiver-plug and movable by a transverse oscillating movementof the said receiver-plug into and out of position to engage with theretaining-abutmentl of the said breech-bolt to hold the breech-bolt inits retired position when the said receiver-plug is turned into positionto bring its lateral opening partly out of registration with the lateralopening in the

